Visible light and microwave light (used in microwave ovens) are different
kinds of electromagnetic (EM) radiation.
(Light is made up of units called photons, and
visible light has more energy per photon than microwave light does.)
Have students
measuring the speed of microwave light... with marshmallows!
Have students compare that speed to the speed of visible light.
How does the speed of light change with the energy per photon of light?
(It doesn't.)